Have now brought together the zx81.rom with the hrg64.p as it was shown here in the forum.
HRGROM.ROM.

The hrgfth.fth file contains all the above HRG commands as inline code.
For EightyOne load as usual under "Load Memory Block" with address 32768 and read
(after TFORTH starts) with "32768 LOAD" who is not the finished HRGTFORTH.P
would like to use.

I do it like this:
- Insert HRGROM.ROM in the EightyOne
- Start
- SHIFT + S key, then appears on the screen HRG and then Return,
then Space and NEW (A key on the PC), the HRG is started.
- Start HRGTFORTH.P
and off you go with the graphic commands.

Here's a routine in TFORTH with sine / cosine to draw a star.
As usual invite the file GRAFIK.FTH to TFORTH (see above).

Start under TFORTH with: 4 HRBANK HRON HRCLR STAR and Return
With HRG64.p you can use Bank 4-7.